1. Field of the Invention
The present invention relates to a system for circulating digital content and more particularly to a system and method for distributing digital content through a network.
Recently, remarkable progress has been achieved in network technique. For example, pictures, music, and the like which are transformed into digitized data can be transmitted with ease and high speed through a network, such as the Internet. Along with this progress, the illegal use, illegal acquisition, leak and the like of the pictures, music, and the like which are transformed into digitized data (hereafter referred to as “digital content”) can be achieved with ease on the Internet so that there is a problem to protect the copyright of the digital content.
2. Related Art
The technique to prevent the illegal use, illegal acquisition, leak and the like of the digital content described above is disclosed in Japanese laid-open publication No. JP10-254909, in which the technique to detect the illegal use of the digital content smoothly by using an electronic watermark to embed not only the copyright information but also the user information on the digital content which is distributed is disclosed.
The published works are permitted to be quoted as long as the profit of the copyrighter is not unfairly infringed. With regard to this point, copyright law provides that some published works can be quoted and thus utilized by others. However, in the conventional art, since the user information is embedded in the digital content even when the digital content is quoted fairly, there is a problem in that the user information can be leaked unintentionally.
In addition, since the method for quoting is not definitely provided in many cases of purchasing the digital content, frequent problems have been caused between the creator of the digital content and the quoter of the digital content.
An object of the present invention is to provide a novel and improved system for distributing digital content and a novel and improved method for distributing digital content, which are capable of preventing the illegal use of the digital content and the leak of the user information.